JP7049652B2 - Water heaters and methods - Google Patents

Description

The present invention relates to a hot water supply device that uses a heat source such as a gas engine or a fuel cell and a heat source such as a water heater in combination.

Exhaust heat from gas engines and fuel cells is exchanged for water supply, and hot water is stored in a hot water storage tank. If the amount of heat is insufficient, hot water is supplied at the set temperature using a water heater. There is a hot water supply system to be realized.
Regarding this hot water supply system, a water heater is provided as an auxiliary heat source on the hot water outlet side of the hot water storage unit (for example, Patent Document 1). When hot water cannot be supplied at the set temperature only with hot water from the hot water storage unit, hot water is supplied at the set temperature by heating with a water heater installed on the downstream side of the hot water storage unit.

Japanese Unexamined Patent Publication No. 2007-31136

By the way, when a water heater, which is an auxiliary heat source, is installed on the downstream side of the hot water storage unit and the hot water temperature is controlled to a set temperature, the hot water temperature is not stable due to a delay in the heating operation by the water heater. Even if the water heater is switched to the heating operation when the hot water from the hot water storage unit reaches the water heater, that is, when it is detected that the hot water temperature is low, it takes time to heat the water heater to the set temperature. , The hot water temperature becomes unstable, for example, the hot water temperature drops below the set temperature.

Even if the notice information about the hot water temperature of the hot water storage unit is given to the water heater side, if the water heater is a direct heating method, preparatory heating cannot be performed before the time of hot water supply demand, so hot water supply lower than the set temperature at the time of hot water supply is possible. There is a problem that
Patent Document 1 does not disclose or suggest such a request or problem, and does not disclose or suggest a structure for solving the request or problem.
Therefore, in view of the above problems, the present invention provides hot water supply at a set temperature by preheating the water supply at a heat source such as a water heater when hot water cannot be discharged at the set temperature only by hot water or heat storage in the hot water storage tank. It is to be realized.

In order to achieve the above object, according to one aspect of the hot water supply device of the present invention, hot water or water is guided from the hot water storage tank and the lower layer side of the hot water storage tank, and heat is exchanged with the heat of the heat source to exchange heat with the upper layer side of the hot water storage tank. The first heat source unit to be returned to, the water supply channel for supplying water to the lower layer side of the hot water storage tank, the second heat source unit installed on the water supply side of the hot water storage tank, and the hot water supply channel for supplying hot water from the upper layer portion of the hot water storage tank. A temperature sensor that detects the temperature of the upper layer of the hot water storage tank, a bypass path that guides the water supply from the water supply channel to the hot water supply path, and a valve opening to either or both of the hot water storage tank or the hot water supply channel. The opening degree of the mixing valve for flowing the water supply and the mixing valve according to the detection temperature of the temperature sensor are adjusted accordingly.
a) Hot water supply only by heating the water supply of the second heat source unit,
b) Mixed hot water supply using the supply water heated in the second heat source and the hot water in the hot water storage tank,
c) A control unit for supplying either water supplied through the second heat source unit without heating or mixed hot water supplied by hot water from the hot water storage tank is provided.
In this hot water supply device, the control unit controls the second heat source unit to be heated or non-heated while adjusting the opening degree of the mixing valve according to the detection temperature of the temperature sensor during hot water supply, and the second heat source unit. The water supply that has passed through may be supplied.

In order to achieve the above object, according to one aspect of the hot water supply device of the present invention, the heat medium is guided from the heat medium tank for storing the heat medium and the lower layer side of the heat medium tank, and heat is exchanged with the heat of the heat source. A heat exchanger that exchanges the heat of the first heat source unit that returns to the upper layer side of the heat medium tank and the heat medium derived from the upper layer part of the heat medium tank with the water supply that flows through the water supply channel, and causes the hot water to flow to the hot water supply channel. The temperature of the second heat source portion installed on the water supply side of the heat exchanger to heat the supply water guided from the water supply channel or allow the water supply to pass through without heating, and the temperature of the upper layer portion of the heat medium tank are detected. A temperature sensor, a bypass path that guides the water supply from the water supply channel to the hot water supply path, a mixing valve that mixes the hot water on the hot water supply path side with the hot water through the bypass path according to the valve opening, and the detection temperature of the temperature sensor. Adjust the opening degree of the mixing valve according to
d) Hot water supply performed by exchanging the heat of the heat medium of the heat medium tank with the water supply.
e) Hot water supply only by heating the water supply of the second heat source unit,
f) It is provided with a control unit for supplying any of mixed hot water of the supply water heated by the second heat source unit and the hot water heated by the heat medium of the heat medium tank.

In order to achieve the above object, according to one aspect of the hot water supply method of the present invention, hot water or water is guided from the hot water storage tank and the lower layer side of the hot water storage tank, and heat is exchanged with the heat of the heat source to exchange heat with the upper layer side of the hot water storage tank. A first heat source unit that returns to the hot water storage tank, a water supply channel that supplies water to the lower layer side of the hot water storage tank, a second heat source unit that heats the water supply, a hot water supply channel that supplies hot water by hot water in the upper layer portion of the hot water storage tank, and the hot water storage tank. A temperature sensor that detects the temperature of the upper layer, a bypass path that guides the water supply from the water supply channel to the hot water supply channel, and either one or both of the hot water storage tank and the hot water supply channel, the water supply flows according to the valve opening. It is a hot water supply method that uses a mixing valve.
The step of adjusting the opening degree of the mixing valve according to the detection temperature of the temperature sensor, and
a) Hot water supply only by heating the water supply of the second heat source unit,
b) Mixed hot water supply using the supply water heated in the second heat source and the hot water in the hot water storage tank,
c) The step includes a step of supplying either water supplied through the second heat source portion without heating or mixed hot water supplied with hot water from the hot water storage tank.
In this hot water supply method, at the time of hot water supply, the opening degree of the mixing valve is adjusted according to the temperature detected by the temperature sensor, the second heat source portion is controlled to be heated or not heated, and the second heat source portion is passed through. The step of supplying the water supply may be included.

In order to achieve the above object, according to one aspect of the hot water supply method of the present invention, the heat medium is guided from the heat medium tank for storing the heat medium and the lower layer side of the heat medium tank, and heat is exchanged with the heat of the heat source. The first heat source unit that returns to the upper layer side of the heat medium tank, the second heat source unit that heats the water supply guided from the water supply channel or allows the water supply to pass through without heating, and the heat derived from the upper layer portion of the heat medium tank. A heat exchanger that exchanges heat of the medium with the water supplied to the water supply channel to flow hot water to the hot water supply channel, a temperature sensor that detects the temperature of the upper layer of the heat medium tank, and the water supply of the water supply channel. A hot water supply method using a bypass path leading to a hot water supply path and a mixing valve that mixes the hot water on the hot water supply path side with the hot water through the bypass path according to the valve opening degree.
The step of adjusting the opening degree of the mixing valve according to the detection temperature of the temperature sensor, and
d) Hot water supply performed by exchanging the heat of the heat medium of the heat medium tank with the water supply.
e) Hot water supply only by heating the water supply of the second heat source unit,
f) The step includes a step of supplying any one of a mixed hot water supply of the supply water heated by the second heat source unit and the hot water heated by the heat medium of the heat medium tank.

According to the invention according to claim 1, claim 2, claim 4 or claim 5, any one of the following effects can be obtained.
(1) Exhaust heat obtained from a gas engine or fuel cell can be converted into hot water, stored in a hot water storage tank, and used for hot water supply, and the stability of hot water supply temperature can be realized.
(2) If it is not possible to supply hot water at the set temperature using only the hot water in the hot water storage tank, heat the water supply at the second heat source located on the water supply side of the hot water storage tank when viewed from the water supply direction of the tap water. Hot water supply can be realized and the hot water supply temperature can be stabilized.
(3) The second heat source can function as an auxiliary heat source for the first heat source that heats the hot water in the hot water storage tank, and it is not possible to supply hot water at the set temperature only with the hot water in the hot water storage tank. Water can be supplied to the hot water storage tank in a heated state, and stable hot water supply at a set temperature can be realized by preheating the water supply at the second heat source.
(4) An inexpensive direct heating type water heater can be used for the second heat source, and even if such a water heater is used, stable hot water supply at a set temperature can be realized and the cost can be suppressed.

According to the invention of claim 3 or claim 6, any one of the following effects can be obtained.
(1) Exhaust heat obtained from a gas engine or fuel cell is converted into a heat medium and stored in a heat medium tank, and the heat of this heat medium can be exchanged for hot water supply to supply hot water, achieving stability in hot water supply temperature. can.
(2) When hot water cannot be supplied at the set temperature only with the heat medium of the heat medium tank, the water supply can be heated by the second heat source unit to realize hot water supply at the set temperature, and the hot water supply temperature can be stabilized.
(3) The first heat source section that heats the heat medium in the heat medium tank can function as an auxiliary heat source in the second heat source section, and hot water can be supplied at the set temperature using only the heat medium in the heat medium tank. In some cases, hot water can be supplied in a non-heated state, and stable hot water supply at a set temperature can be realized by preheating the water supply at the second heat source unit.
(4) An inexpensive direct heating type water heater can be used for the second heat source, and even if such a water heater is used, stable hot water supply at a set temperature can be realized and the cost can be suppressed.
And other objects, features and advantages of the present invention will be further clarified by reference to the accompanying drawings and each embodiment.

It is a figure which shows the hot water supply apparatus which concerns on 1st Embodiment. It is a figure which shows the hot water supply device which concerns on Example. It is a figure which shows the control part of a hot water supply device. It is a flowchart which shows the processing procedure of the hot water storage process. It is a flowchart which shows the processing procedure of FB control. It is a flowchart which shows the processing procedure of a hot water supply process. It is a figure which shows the hot water supply pattern 1. It is a figure which shows the hot water supply pattern 2. It is a figure which shows the hot water supply apparatus which concerns on 2nd Embodiment. It is a flowchart which shows the processing procedure of a hot water supply device.

[First Embodiment]
FIG. 1 shows a water heater according to the first embodiment. The configuration shown in FIG. 1 is an example, and the present invention is not limited to such a configuration.
In the hot water supply device 2 according to the first embodiment, the hot water HW stored in the hot water storage tank 4 is used for hot water supply. The hot water supply device 2 includes, for example, a hot water storage tank 4, a first heat source unit 6, a water supply channel 8, a second heat source unit 10, a hot water supply channel 12, a temperature sensor 14, a bypass path 16, a mixing valve 18, and a control unit 20. ..
Hot water HW is stored in the hot water storage tank 4. The first heat source unit 6 uses a fuel cell unit, an engine generator, a heat pump, or the like as a heat source, exchanges heat (exhaust heat, etc.) with the water supply W, and generates hot water HW from the water supply W. In this example, the hot water HW or the water supply W is guided from the lower layer side of the hot water storage tank 4, and the hot water HW obtained by exchanging heat with the heat of the heat source is returned to the upper layer side of the hot water storage tank 4.

A water supply channel 8 is provided on the lower layer side of the hot water storage tank 4, and the water supply W is guided to the lower layer side of the hot water storage tank 4. The second heat source unit 10 provided in the water supply channel 8 exchanges heat with the water supply W by using combustion heat or the like as a heat source, but has a function of passing the water supply W in an unheated state. The second heat source unit 10 may be provided with, for example, a water heater of a direct heating type.
A hot water supply channel 12 is connected to the hot water storage tank 4. The hot water supply channel 12 supplies hot water HW on the upper layer side of the hot water storage tank 4. The hot water supply passage 12 is provided with a temperature sensor 14, and the temperature sensor 14 detects the temperature of the hot water HW discharged from the upper layer side of the hot water storage tank 4.

A bypass path 16 is provided between the water supply channel 8 and the hot water supply channel 12 between the hot water storage tank 4 and the second heat source section 10, and the bypass path 16 is the hot water HW from the second heat source section 10 or the second heat source section 10. This is a water channel that guides the water supply W that has passed through the water supply channel 12 to the hot water supply channel 12. In this example, a mixing valve 18 is provided at a branch point between the water supply passage 8 and the bypass passage 16. The water supply W or hot water HW that has passed through the second heat source portion 10 flows through the mixing valve 18. In this mixing valve 18, the opening ratio of the port on the hot water storage tank 4 side and the port on the bypass path 16 side is adjusted, and the water supply W or hot water HW of the water supply channel 8 is the hot water storage tank 4 or the bypass path 16 according to the opening ratio. It is guided to either one or both. The flow rate of the bypass path 16 is adjusted by the opening degree of the mixing valve 18 on the bypass path 16 side. The water supply W or hot water HW guided to the bypass passage 16 joins the hot water supply passage 12, and the hot water HW from the hot water storage tank 4 can be mixed.
Then, the control unit 20 controls the second heat source unit 10 and the mixing valve 18 according to the detection temperature of the temperature sensor 14. According to the control unit 20, the opening degree of the mixing valve 18 is adjusted according to the detection temperature of the temperature sensor 14.
a) Hot water supply only by heating the water supply of the second heat source unit 10,
b) Water supply W (hot water HW) hot water supply that was preheated by the second heat source unit 10
c) Either the water supply W that has passed through the second heat source unit 10 without heating or the mixed hot water supply by the hot water HW of the hot water storage tank 4 is performed.
In such control, according to the control unit 20, the opening degree of the mixing valve 18 is adjusted according to the detection temperature of the detection temperature of the temperature sensor 14, and the second heat source unit 10 is controlled to be in a heated state or a non-heated state. The water supply W that has passed through the second heat source unit 10 is supplied to the hot water storage tank 4.

<Hot water supply method>
This hot water supply method is a hot water supply method using the above-mentioned hot water storage tank 4, first heat source unit 6, water supply channel 8, second heat source unit 10, hot water supply channel 12, temperature sensor 14, bypass path 16, and mixing valve 18. ,
First, it includes a step of adjusting the opening degree of the mixing valve 18 according to the detection temperature of the temperature sensor 14, and secondly, a step of supplying hot water based on the opening degree adjustment.
In the second step, as mentioned above,
a) Hot water supply only by heating the water supply of the second heat source unit 10,
b) Water supply W (hot water HW) hot water supply that was preheated by the second heat source unit 10
c) Either the water supply W that has passed through the second heat source unit 10 without heating or the mixed hot water supply by the hot water HW of the hot water storage tank 4 is supplied.

In this hot water supply method, as a third step, the opening degree of the mixing valve 18 is adjusted according to the detection temperature of the temperature sensor 14, and the second heat source portion 10 is controlled to be heated or not heated, and as a fourth step. , Hot water HW or water supply W is supplied. In the fourth step, the water supply W that has passed through the second heat source unit 10 is supplied to the hot water storage tank 4.

<Effect of the first embodiment>
According to this first embodiment, the following effects can be obtained.
(1) Exhaust heat obtained from a gas engine or fuel cell can be converted into hot water and stored in a hot water storage tank, which can be used for hot water supply and stabilize the hot water supply temperature.
(2) When the hot water of the hot water storage unit cannot supply hot water at the set temperature, the hot water supply at the set temperature can be realized and the hot water supply temperature can be stabilized by heating the water supply at the second heat source unit.
(3) The temperature of hot water can be supplemented by the auxiliary heating of the first heat source part and the second heat source part, and stable hot water supply at the set temperature can be realized by using the preheating of the water supply by the second heat source part.
(4) If an inexpensive direct heating water heater is used for the second heat source, stable hot water supply at the set temperature and cost reduction can be achieved.

<Water heater 2>
FIG. 2 shows a water heater 2 according to an embodiment of the first embodiment. In FIG. 2, the same parts as those in FIG. 1 are designated by the same reference numerals. The configuration shown in FIG. 2 is an example, and the present invention is not limited to such a configuration.
The hot water storage unit 22 is provided with a hot water storage tank 4, a hot water supply passage 12, a bypass passage 16-1, and a mixing valve 18-1. In the hot water storage tank 4, a plurality of temperature sensors 14-1, 14-2, 14-3, 14-4 are installed at intervals from the upper layer side to the lower layer side, and the hot water HW in the layer heat storage state is installed. The temperature of each part is detected.
The water supply channel 8 is provided with a flow rate sensor 24-1 and a temperature sensor 14-5. Temperature sensors 14-6 and 14-7 are provided on the hot water supply channel 12 side.

The first heat source unit 6 is provided with, for example, a fuel cell unit 26. The fuel cell unit 26 is provided with a fuel cell 28 and a heat exchanger 30. In the circulation path 32, the hot water HW or the water supply W taken out from the lower layer side of the hot water storage tank 4 is heat-exchanged by the heat exchanger 30, and then the heated hot water HW is circulated to the upper layer side of the hot water storage tank 4. In the heat exchanger 30, the heat of the exhaust gas generated in the fuel cell 28 is exchanged with the hot water HW or the water supply W on the lower layer side of the hot water storage tank 4.
The second heat source unit 10 is provided with a water heater 34. The water heater 34 is provided with a heat exchanger 36, a burner 38, a bypass path 16-2, a mixing valve 18-2, a flow rate sensor 24-2, and temperature sensors 14-8, 14-9, and 14-10. The heat exchanger 36 exchanges heat from the combustion of the burner 38 with the water supply W. The bypass path 16-2 merges the water supply W before heat exchange in the heat exchanger 36 with the hot water HW after heat exchange. The mixing ratio of the water supply W and the hot water HW is adjusted in the mixing valve 18-2 by adjusting the opening degree on the heat exchanger 36 side and the opening degree of the bypass path 16-2. This mixing ratio is adjusted by the control of the control unit 20 (FIG. 1), that is, by the required temperature of the hot water HW to the hot water storage unit 22 side required for the preceding heating.
The flow rate sensor 24-2 detects the flow rate of the water supply W, and the temperature sensor 14-8 detects the water supply temperature. The temperature sensor 14-9 detects the temperature on the exit side of the heat exchanger 36, and the temperature sensor 14-10 detects the temperature of the hot water HW entering the hot water storage unit 22 from the water heater 34.

In the hot water supply device 2, the water supply W is supplied to the water heater 34 prior to the hot water storage tank 4, and the water supply W that has passed through the water heater 34 or the hot water HW obtained by the water heater 34 is supplied to the hot water storage unit 22.
The fuel cell unit 26 exchanges heat with the hot water HW or water supply W on the lower layer side of the hot water storage tank 4 with the heat of the exhaust gas generated during battery operation, and returns the heated hot water HW to the upper layer side of the hot water storage tank 4. The temperature of the hot water HW heated by the fuel cell unit 26 is in the range of 70 ° C. to 80 ° C., for example, 75 ° C.

<Control unit 20>
FIG. 3 shows an example of the control unit 20 (FIG. 1). The control unit 20 includes a battery control unit 40, a hot water storage control unit 42, a hot water supply control unit 44, and a remote control unit 46, which are equipped with a computer and have a communication function and are linked by wire or wireless to detect temperatures. Information such as the operating status is exchanged.
The battery control unit 40 is provided in the fuel cell unit 26, and performs a power generation function of the fuel cell, exhaust control for passing through the heat exchanger 30, and the like.
The hot water storage control unit 42 is provided in the hot water storage unit 22. The control of the hot water storage control unit 42 includes an opening degree control of the mixing valve 18-1 and the like.
The hot water supply control unit 44 includes a combustion control unit 48, and the hot water supply control includes linkage control including transmission / reception of information with the battery control unit 40, the hot water storage control unit 42, and the remote control unit 46, combustion control of the burner 38, and a mixing valve. 18-2 opening adjustment and the like are included.
The remote control unit 46 is provided in the remote control device 50. The control of the remote control unit 46 includes linked control including transmission / reception of information with the battery control unit 40, the hot water storage control unit 42, and the hot water supply control unit 44, as well as remote control display control and the like.

<Hot water storage treatment>
FIG. 4 shows a processing procedure for the hot water storage unit 22. In this processing procedure, when controlling hot water storage, information such as the detected temperature information of the temperature sensors 14-1 to 14-7 and the status of hot water supply operation is transmitted and received (S101). In the processing procedure, S indicates the process, and the number assigned to S indicates the process order (the same applies hereinafter).
After this information exchange, it is determined by using the detection signal of the flow rate sensor 24-1 whether or not the hot water supply by the faucet or the shower has occurred (S102).
If hot water supply is used (YES in S102), the water entry temperature to the hot water storage unit 22 is compared with (set temperature-T1), and it is determined whether the water entry temperature ≥ (set temperature-T1) (S103). T1 ° C. is, for example, 1 ° C., and it is assumed that the temperature drops due to piping loss. According to this S103, it is determined from the detection temperature of the temperature sensor 14-5 whether or not the water heater 34 is discharging hot water at the set temperature.

As a result of this determination, if the water entry temperature ≥ (set temperature-T1) (YES in S103), the port on the hot water storage tank 4 side of the mixing valve 18-1 is closed, and the bypass path 16-is provided with the water supplied from the water heater 34. Hot water is supplied from 1 to the hot water supply channel 12 (S104).
As a result of this determination, if the water entry temperature <(set temperature-T1) (NO in S103), hot water is supplied by FB (Feedback) control by adjusting the opening degree of the mixing valve 18-1 (FIG. 5). S105). That is, the hot water HW from the hot water storage tank 4 is mixed with the water supplied from the water heater 34 (water supply W or hot water HW), and the mixed hot water supplied to the set temperature is performed.
If the hot water supply is not used at the discretion of S102 (NO in S102), the mixing valve 18-1 is set to a predetermined opening position, for example, to stand by at the current position (S106). At this time, the supply of the water supply W is stopped.

<FB control>
FIG. 5 shows hot water supply control by FB control as a processing procedure of FB control related to the hot water storage unit 22. In this FB control, the mixing valve 18-1 is controlled as the outlet hot water temperature> the inlet temperature of the hot water storage tank 4 regardless of the detected temperatures of the temperature sensors 14-5 and the temperature sensors 14-6.
At this time, the detected temperature of the temperature sensor 14-7 is taken in (S201), and it is determined whether the hot water supply temperature> the set temperature (S202). Here, the hot water supply temperature is the detected temperature of the temperature sensor 14-7, the set temperature is the temperature set by the user, and this temperature has a temperature range of, for example, about ± 0.5 ° C.
If the hot water supply temperature> the set temperature (YES in S202), the opening ratio of the mixing valve 18-1 is adjusted to a position where the bypass path 16-1 side is increased (S203), and the mixture returns to S105 in FIG. In this case, the adjustment is to lower the hot water supply temperature, but the adjustment amount may be adjusted depending on the temperature difference.

If the hot water supply temperature is not the set temperature (NO in S202), it is determined whether the hot water supply temperature is the set temperature (S204). If the hot water supply temperature <the set temperature (YES in S204), the opening ratio of the mixing valve 18-1 is adjusted to a position where the bypass path 16-1 side is reduced (S205), and the mixture returns to S105 in FIG.
Further, if the hot water supply temperature is not equal to the set temperature (NO in S204), since hot water is supplied according to the set temperature, S205 is skipped without adjusting the opening ratio of the mixing valve 18-1 and FIG. 4 shows. Return to S105.
As described above, the FB control by the mixing valve 18-1 is executed on the premise that the outlet hot water temperature on the hot water storage tank 4 side is higher than the inlet temperature regardless of the outlet hot water temperature and the water inlet temperature of the hot water storage tank 4. Therefore, when the hot water supply temperature is lowered, the mixing valve 18-1 reduces the opening degree on the hot water storage tank 4 side to increase the opening degree on the bypass path 16 side, and when the hot water supply temperature is raised, the opposite is true. That is, the opening degree on the hot water storage tank 4 side is increased and the opening degree on the bypass path 16 side is decreased.

<Water heater processing>
FIG. 6 shows a processing procedure relating to the water heater 34. In this water heater processing, after exchanging information (S301), it is determined whether hot water is used (S302). In S301, information such as the detection temperature of the temperature sensor and the operating state of the water heater 34 is transmitted and received, and the information of other devices is grasped. In S302, as described above, it may be determined from the detected flow rate of the flow rate sensor 24-2 whether or not the hot water supply demand is generated by opening the faucet or the shower.
When using hot water supply (YES in S302), it is determined whether the water heater 34 is in the heating operation (S303).
If the heating operation is not in progress (NO in S303), it is determined whether the heat storage of the hot water storage tank 4 is insufficient (S304). Whether or not the heat storage is insufficient may be determined by the detection temperature of either or both of the temperature sensor 14-6 and the temperature sensor 14-1. Unless the heat storage of the hot water storage tank 4 is insufficient (NO in S304), the water supply W is not heated by the water heater 34, the port on the heat exchanger 36 side of the mixing valve 18-2 is closed, and hot water is stored from the bypass path 16-2. The water supply W is supplied to the unit 22 (S305). If the heat storage of the hot water storage tank 4 is insufficient (YES in S304), the hot water HW heated to the set temperature by the water heater 34 is supplied to the hot water storage unit 22 (S307).

In S303, if the heating operation is in progress (YES in S303), it is determined whether the heat storage in the hot water storage tank 4 is restored (S306). If the heat storage of the hot water storage tank 4 is still insufficient (NO in S306), hot water is supplied by hot water HW heated to a set temperature by the water heater 34 (S307). In this case, hot water may be supplied at a temperature obtained by adding the above-mentioned temperature (T1) to the set temperature, assuming heat dissipation loss due to piping.
If the heat storage of the hot water storage tank 4 is restored (YES in S306), it is determined whether the hot water storage unit 22 is in the FB control operation (whether S105 in FIG. 4 is in the execution state) (S308). If the FB control operation of the hot water storage unit 22 is not performed (NO in S308), the water heater 34 heats the hot water storage unit 22 to (set temperature −T2) to supply hot water (S309). Here, the temperature T2> T1, but it is preferable that the temperature T2 is low.

When it is determined in S302 that hot water supply is not used (NO in S302) or when it is determined in S308 that the FB control operation of the hot water storage unit 22 is not used (YES in S308), the heating operation of the water heater 34 is shifted to the stopped state (S310). ).
In this hot water supply process, in S304, it is determined whether or not the hot water storage unit cannot or is likely to be unable to supply hot water at the set temperature unless the heating operation is in progress. In this determination, for example, it is determined whether or not the detected temperature (= Th1) of the temperature sensor 14-1 of the hot water storage unit 22 is lower than the set temperature (Th1 <set temperature). It should be noted that this determination may be performed on the hot water supply control unit 44 side of the water heater 34 side by acquiring the temperature information of the hot water storage unit 22, or may be performed on the hot water storage control unit 42 side of the hot water storage unit 22.

In S305, if the hot water HW of the hot water storage unit 22 can supply hot water at a set temperature, the water heater 34 does not heat the water, and the water supplied to the water heater 34 (water supply W or hot water HW) is supplied to the hot water storage unit 22. Supply. In S306, if the water heater 34 is in the heating operation, it is determined whether the hot water HW of the hot water storage unit 22 can supply hot water at a set temperature. This determination may be made, for example, depending on whether the detected temperature (= Th2) of the temperature sensor 14-2 of the hot water storage unit 22 is equal to or higher than the set temperature (Th2 ≧ set temperature). This determination may be performed by the hot water supply control unit 44 that has acquired the temperature information of the hot water storage unit 22, or may be performed by the hot water storage control unit 42 of the hot water storage unit 22. This determination may be performed using the detection temperature of the temperature sensor 14-1, but a hysteresis is set for the determination of S306.
In S307, hot water is discharged at a set temperature by the heating operation by the water heater 34, and in this case, the hot water HW of the hot water storage tank 4 is not used (corresponding to S104 in FIG. 4).
Then, if the hot water storage unit 22 is in the FB control operation in S308, the control of S310 may be selected.

And the control of S308 is not always necessary. That is, if the hot water HW of the hot water storage tank 4 shifts from a state in which hot water cannot be supplied at the set temperature to a state in which hot water can be supplied at the set temperature, unheated water is supplied even if it takes time to switch the mixing valve 18-1. Can be reduced. If the response performance of the mixing valve 18-1 is high and the piping route from the upper layer side of the hot water storage tank 4 to the mixing valve 18-1 is short, there is no problem in shifting to S310 by omitting S308. S308 is a determination for the hot water storage unit 22 to supply hot water at a temperature slightly lower than the set temperature (for example, the set temperature of about -3 ° C) until the hot water supply from the water heater 34 is completed and the FB control is started.
In S309, hot water is supplied from the water heater 34 to supply hot water at a temperature slightly lower than the set temperature (for example, the set temperature -3 ° C). This temperature is the temperature in the case of NO in S103 of FIG. In S310, the hot water HW of the hot water storage tank 4 can supply hot water at a set temperature, so that the heating operation by the water heater 34 becomes unnecessary.

<Hot water supply pattern 1>
FIG. 7 shows the hot water supply pattern 1. In FIG. 7, the active portion is indicated by a solid line, and the dormant portion is indicated by a broken line. This hot water supply pattern 1 is hot water supply from hot water supply W to hot water HW when hot water supply can be performed using the hot water HW of the hot water storage tank 4. In this case, it is possible to pass the water supply W through the heat exchanger 36 while the water heater 34 is controlled to be in a non-heated state, but in order to avoid dew condensation, the mixing valve 18-2 has a bypass path 16-2. The opening on the side is set to 100 [%] to avoid water flow to the heat exchanger 36.

<Hot water supply pattern 2>
FIG. 8 shows the hot water supply pattern 2. In FIG. 8, as in FIG. 7, the active portion is indicated by a solid line, and the dormant portion is indicated by a broken line. This hot water supply pattern 2 is hot water supply when hot water cannot be supplied by the hot water HW of the hot water storage tank 4. In this case, even if the hot water HW of the hot water storage tank 4 has heat storage, the hot water supply temperature of the water heater 34 is set to the set temperature and hot water is supplied. In this case, the mixing valve 18-1 has an opening degree of 100 [%] on the bypass path 16-1 side, and water is not supplied to the hot water storage tank 4.

<Effect of Examples>
According to this embodiment, the following effects can be obtained.
(1) The hot water supply temperature can be stabilized by installing the water heater 34, which is an auxiliary heat source, for the hot water storage unit 22 on the upstream side when viewed from the water supply side and preheating the water supply W.
(2) When the detected temperature of the hot water HW of the hot water storage tank 4 falls below a predetermined temperature while the hot water supply is in use, the water heater 34 is operated. That is, the temperature of the hot water supply can be quickly stabilized only by operating the water heater 34 before the heat storage amount of the hot water storage tank 4 is exhausted.
(3) The time lag until hot water supply by the water heater 34 allows the hot water storage tank 4 to function as a buffer for the residual heat, and the opening of the mixing valve 18-1 is adjusted according to the change in the water inlet temperature to adjust the opening of the hot water storage unit 22 side. It is possible to switch from the hot water supply of the above to the heat source by the water heater 34, that is, the heated hot water supply.
(4) When the heat storage of the hot water storage tank 4 is restored, the hot water supply output of the water heater 34 is suppressed and finally stopped, so that the hot water storage unit 22 is controlled by the mixing valve 18-1 according to the change in the water inlet temperature. It is possible to switch from the heated hot water supply by the water heater 34 to the hot water storage unit 22, that is, the heat storage hot water supply.

[Second Embodiment]
FIG. 9 shows the water heater 2 according to the second embodiment. In this water heater 2, the same parts as those in FIG. 2 or FIG. 3 are designated by the same reference numerals.
In the hot water supply device 2 according to the second embodiment, the hot water HW stored in the hot water storage tank 4 is an example of a heat medium, and this hot water HW is used only as a heat source for heating the water supply W and is used for hot water supply. Only the water supply W is used.
The hot water storage tank 4 is provided with a circulation path 52, and the circulation path 52 is provided with a circulation pump 54 and a heat exchanger 56. A circulation pump 54 is driven, and hot water HW as a heat medium is taken out from, for example, the upper layer side of the hot water storage tank 4 and circulated to the lower layer side in the circulation path 52.
The hot water HW of the hot water storage tank 4 is used as a heat medium, and the heat of the hot water HW is exchanged with the hot water HW or the water supply W flowing through the hot water supply passage 12-1 by the heat exchanger 56.
A bypass passage 16-1 is provided between the hot water supply passage 12-2 and the hot water supply passage 12-1, and the hot water HW or the water supply W flowing from the bypass passage 16-1 to the hot water supply passage 12-2 is a mixing valve 18-. It is adjusted by the opening degree of 1.

Then, in this hot water supply device 2, the control unit 20 (FIG. 3) is provided as in the first embodiment, and the opening degree of the mixing valve 18-1 is adjusted according to the detection temperature of the temperature sensor 14-1.
d) Hot water supply performed by exchanging heat from the hot water HW of the hot water storage tank 4 with the water supply W.
e) Hot water supply in which the water supply W is preheated by the water heater 34 f) Hot water supply in which one of the water supply W preheated by the water heater 34 and the hot water HW heated by the hot water HW of the hot water storage tank 4 is supplied.
Therefore, if such a hot water supply device 2 is used, the heat of the hot water HW stored in the hot water storage tank 4 can be used for hot water supply heating.

<Processing procedure>
FIG. 10 shows a procedure for processing hot water supply according to the hot water storage unit 22 of the second embodiment. This treatment procedure is an example of the hot water supply method of the present invention, and in this hot water supply treatment, after exchanging information (S401), it is determined whether or not hot water supply is used (S402). In S401, information such as the detection temperature of the temperature sensor and the operating state of the water heater 34 is transmitted and received, and the information of other devices is grasped. In S402, it may be determined from the detected flow rate of the flow rate sensor 24-1 whether or not the demand for hot water supply is generated by opening the faucet or the shower as described above.
When using hot water supply (YES in S402), it is determined whether the water entry temperature ≧ (set temperature −T1) (S403). T1 is, for example, 1 ° C., and heat dissipation loss of the pipe is assumed. In this S403, it is determined whether or not the water heater 34 is discharging hot water at the set temperature.
If the water entry temperature ≥ (set temperature −T1) (YES in S403), the circulation pump 54 is stopped (S404). In this case, the port on the heat exchanger 56 side of the mixing valve 18-1 is closed, and hot water is supplied from the bypass passage 16-1 to the hot water supply passage 12-2 with the water supplied from the water heater 34 (for example, hot water HW) (S405). ..

In S403, if the water entry temperature <(set temperature-T1) (NO in S403), the detected temperature of the temperature sensor 14-6, that is, the temperature after heat exchange in the heat exchanger 56 is set to the set temperature + 6 ° C. The circulation pump 54 is controlled to reach the temperature (S406), and the FB control by the mixing valve 18-1 is executed (S407).
In S402, if hot water supply is not used (NO in S402), the circulation pump 54 is stopped (S408), and the mixing valve 18-1 is made to stand by at a predetermined opening position (S409).
In this processing procedure, the control on the water heater 34 side is basically the same as the water heater control described above (FIG. 6). However, in the first embodiment, the heat storage state of the hot water storage unit is compared with the detected temperature (= Th1, Th2) of the temperature sensors 14-1 and 14-2, but in this second embodiment, the set temperature is compared. It is compared with a predetermined temperature higher than the set temperature (the temperature at which the temperature of the hot water HW after heat exchange in the heat exchanger 56 can be set to (set temperature + 6 ° C.)). (Set temperature + 6 ° C.) is an example, and the present invention is not limited to this value.

<Effect of the second embodiment>
According to this second embodiment, the following effects can be obtained.
(1) In this way, even in the indirect hot water supply method, by adjusting the opening degree of the mixing valve 18-1 according to the detection temperature of the heat medium,
d) Hot water supply performed by exchanging heat from the hot water HW (heat medium) of the hot water storage tank 4 with the water supply W.
e) Hot water supply in which water is preheated by the water heater 34 (second heat source unit 10),
f) It is possible to supply either hot water that is previously heated by the water heater 34 (second heat source unit 10) and hot water that is heated by the heat medium of the heat medium tank, and stable hot water can be supplied. can.
(2) Indirect heating type water heaters can stabilize the hot water temperature by switching the heat source, but the price is high due to the large number of parts such as liquid heat exchangers and heating circuits, and the single function of hot water supply is available. There was a problem that the equipment was limited because the bath water heater could not handle it, but such a problem can be solved by preheating the water supply W by the water heater 34 without increasing the number of parts of the hot water supply device 2. , Stable hot water supply at the set temperature can be realized.

As described above, the hot water supply device and the most preferable embodiment of the method have been described. The present invention is not limited to the above description. Various modifications and modifications can be made by those skilled in the art based on the gist of the invention described in the claims or disclosed in the form for carrying out the invention. Needless to say, such modifications and modifications are included in the scope of the present invention.

According to this hot water supply device and hot water supply method, the hot water temperature of the hot water storage tank is lowered, and the decrease in the hot water supply temperature of the hot water can be supplemented by the preheating of the hot water supply, and stable hot water supply at the set temperature can be realized.

2 Water heater 4 Hot water storage tank 6 First heat source 8 Water supply channel 10 Second heat source 12 Hot water supply channel 14, 14-1, 14-2, 14-3, 14-4, 14-5, 14-6, 14- 7, 14-8, 14-9, 14-10 Temperature sensor 16, 16-1, 16-2 Bypass path 18, 18-1, 18-2 Mixing valve 20 Control unit 22 Hot water storage unit 16-1, 16-2 Bypass path 24-1, 24-2 Flow sensor 26 Fuel cell unit 28 Fuel cell 30, 36, 56 Heat exchanger 32 Circulation path 34 Water heater 38 Burner 40 Battery control unit 42 Hot water storage control unit 44 Hot water supply control unit 46 Remote control unit 48 Combustion control unit 50 Remote control device 52 Circulation path 54 Circulation pump 56 Heat exchanger

Claims (6)

With a hot water storage tank
A first heat source unit that guides hot water or water from the lower layer side of the hot water storage tank, exchanges heat with the heat of the heat source, and returns it to the upper layer side of the hot water storage tank.
A water supply channel that supplies water to the lower layer side of the hot water storage tank,
The second heat source unit installed on the water supply side of the hot water storage tank,
A hot water supply channel that supplies hot water from the hot water in the upper layer of the hot water storage tank,
A temperature sensor that detects the temperature of the upper layer of the hot water storage tank, and
A bypass path that guides the water supply from the water supply channel to the hot water supply channel,
A mixing valve that flows the water supply to either or both of the hot water storage tank and the hot water supply channel according to the valve opening degree.
The opening degree of the mixing valve is adjusted according to the detection temperature of the temperature sensor.
a) Hot water supply only by heating the water supply of the second heat source unit,
b) Mixed hot water supply using the supply water heated in the second heat source and the hot water in the hot water storage tank,
c) A control unit that supplies either water supplied through the second heat source unit without heating or mixed hot water supplied with hot water from the hot water storage tank.
A water heater characterized by being equipped with. At the time of hot water supply, the control unit adjusts the opening degree of the mixing valve according to the temperature detected by the temperature sensor, controls the second heat source unit to be heated or not heated, and allows the second heat source unit to pass through the second heat source unit. The hot water supply device according to claim 1, wherein water is supplied. A heat medium tank that stores the heat medium and
A first heat source unit that guides a heat medium from the lower layer side of the heat medium tank, exchanges heat with the heat of the heat source, and returns it to the upper layer side of the heat medium tank.
A heat exchanger that exchanges the heat of the heat medium derived from the upper layer of the heat medium tank with the water supply flowing through the water supply channel and causes the hot water to flow to the hot water supply channel.
A second heat source unit installed on the water supply side of the heat exchanger to heat the water supply guided from the water supply channel or allow the water supply to pass through without heating.
A temperature sensor that detects the temperature of the heat medium in the upper layer of the heat medium tank, and
A bypass path that guides the water supply from the water supply channel to the hot water supply channel,
A mixing valve that mixes the water supply with the hot water on the hot water supply path side through the bypass path according to the valve opening.
The opening degree of the mixing valve is adjusted according to the detection temperature of the temperature sensor.
d) Hot water supply performed by exchanging the heat of the heat medium of the heat medium tank with the water supply.
e) Hot water supply only by heating the water supply of the second heat source unit,
f) A control unit that performs either mixed hot water supply of the supply water heated by the second heat source unit and the hot water heated by the heat medium of the heat medium tank, and the control unit.
A water heater characterized by being equipped with. A first heat source unit that guides hot water or water from the lower layer side of the hot water storage tank, exchanges heat with the heat of the heat source and returns it to the upper layer side of the hot water storage tank, and a water supply channel that supplies water to the lower layer side of the hot water storage tank. A second heat source unit for heating the water supply, a hot water supply channel for supplying hot water by the hot water in the upper layer of the hot water storage tank, a temperature sensor for detecting the temperature of the upper layer of the hot water storage tank, and the hot water supply in the water supply channel. A hot water supply method using a bypass path leading to a path and a mixing valve that flows the water supply to either or both of the hot water storage tank and the hot water supply path according to the valve opening degree.
The step of adjusting the opening degree of the mixing valve according to the detection temperature of the temperature sensor, and
a) Hot water supply only by heating the water supply of the second heat source unit,
b) Mixed hot water supply using the supply water heated in the second heat source and the hot water in the hot water storage tank,
c) A step of supplying either water supplied through the second heat source portion without heating or mixed hot water supplied with hot water from the hot water storage tank.
A hot water supply method characterized by including. During hot water supply, the opening degree of the mixing valve is adjusted according to the temperature detected by the temperature sensor, and the second heat source unit is controlled to be heated or not heated.
The step of supplying the water supply that has passed through the second heat source portion, and
The hot water supply method according to claim 4, wherein the hot water supply method comprises. It is guided from a heat medium tank that stores the heat medium, a first heat source portion that guides the heat medium from the lower layer side of the heat medium tank, exchanges heat with the heat of the heat source, and returns it to the upper layer side of the heat medium tank, and a water supply channel. Hot water is supplied by exchanging heat between the second heat source unit that heats the water supply or allows the water supply to pass unheated and the heat medium derived from the upper layer of the heat medium tank to the water supply that flows through the water supply channel. A heat exchanger that flows through the path, a temperature sensor that detects the heat medium temperature in the upper layer of the heat medium tank, a bypass path that guides the water supply from the water supply channel to the hot water supply path, and the bypass path according to the valve opening degree. It is a hot water supply method using a mixing valve that mixes the hot water with the hot water on the hot water supply path side.
The step of adjusting the opening degree of the mixing valve according to the detection temperature of the temperature sensor, and
d) Hot water supply performed by exchanging the heat of the heat medium of the heat medium tank with the water supply.
e) Hot water supply only by heating the water supply of the second heat source unit,
f) A step of performing either a mixed hot water supply of the supply water heated in the second heat source portion and the hot water heated by the heat medium of the heat medium tank, and
A hot water supply method characterized by including.

Images